Electric heater



Nov. 13, 1934. RJANDIERSO'NI 1,930,554

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IN V EN TOR.

BY 7(1) 2&4

A TTORNEYS.

Patented Nov. 13, 1934 UNITED STATES PATENT OFFICE ELECTRIC HEATERApplication May 19, 1932, Serial No. 612,191

3 Claims.

The present invention is designed to improve electric hot plates,particularly hot plates which may be used upon their upper surface forconducting heat to an article supported thereon and 6 which on theirunder-surface may be used to directly radiate the heat to an articlebelow the plate. Such plates may be used in ovens and in such uses easeof assembly and cheapness of construction are of very great importance.In the present invention, the heating element may be supported in a veryeconomical way and the assembly of the parts-be expeditiouslyaccomplished with a very secure assembly when accomplished. Features anddetails of the invention will appear from the specification and claims.

A preferred embodiment of the invention is illustrated in theaccompanying drawing as follows:

Fig. 1 shows a vertical section through the plate on the line 11 in Fig.2.

Fig. 2 a plan view of the bottom of the plate.

Fig. 3 a section on the line 33 in Fig. 2.

1 marks the plate and 2 a depending skirt, or flange extending aroundthe plate.

Metal strips 3 extend across and are secured to the under-side of theplate. Preferably these strips are folded strips having outwardlyextending flanges 4 at the open edge. These flanges are preferablysecured to the plate by spot welding. The folded edge of the plate has aseries of notches 5.

Insulating sleeves, or tubes 6 ordinarily formed of porcelain are seatedin the notches. These tubes have shoulders 7 which are arranged betweenthe walls of the folded metal strip and thus lock the strip against endmovement out of engagement with the strip.

With the tubes seated in the strip a wire 8 is inserted along the fold 9of the metal strip, the wire bridging the notches and locking thesleeves in the notches. This forms a very convenient locking device, onethat can be very readily inserted and one that very definitely securesthe tubes in place when inserted.

An electric heating element 10 is threaded through the tubes in a,circuitous path back and 60 forth through the sleeves on adjacentplates, thus covering with fair uniformity the entire surface of theplate. The elements terminate in electric terminals 11 arranged in theskirt, or flange along one side of the plate.

What I claim as new is:

1. In an electric heater, the combination of a plate; supporting metalstrips secured to the plate, said strips being folded and having theopen edges of the strips secured to the plate, the folded edges of thestrips being provided with notches; insulating blocks arranged in thenotches; a wire extending within and along the fold of the metal stripsand locking the blocks in the notches; and a heating element extendingfrom block to block and secured in the blocks.

2. In an electric heater, the combination of a plate; supporting metalstrips, said strips being folded and having flanges along the openedges, the folded edges of the strips being provided with notches andthe flanges of the strips being secured to the plate; insulating blocksseated in the notches, said blocks having shoulders arranged between thewalls of the strip; a wire extending within and along the folds lockingthe blocks in St the notches; and a heating element extending from blockto block and secured in the blocks.

3. In an electric heater, the combination of a supporting metal strip,said strip being folded longitudinally of the strip, the folded edge ofthe strip being provided with a series of notches; insulating blocksarranged in the notches; a wire extending within and along the foldlocking the blocks in the notches; and a heating element secured in saidblocks.

CARLR. ANDERSON.

